1. Field of Invention
The field of the currently claimed embodiments of this invention relates to systems and methods for separating and determining sizes of particles in a sample, and more particularly hydrodynamic systems and methods for separating and determining sizes of particles in a sample.
2. Discussion of Related Art
The dominant conventional methods of DNA sizing and separation are dependent on electrophoresis and/or chromatography. The most common method, slab gel electrophoresis, is convenient but has limited DNA sizing resolution, poor detection sensitivity, limited quantitative accuracy, and cannot be used to size large DNA molecules. Pulsed field gel electrophoresis can be used to size large DNA molecules but has long run times and poor quantitative accuracy. Capillary electrophoresis (CE) has very high DNA sizing resolution, high detection sensitivity, and fast run times. However, it is complex and requires expensive instrumentation, viscous sieving matrices, and functionalized capillaries. Reproducibility can also be problematic due to sensitivity to capillary wall properties.
Capillary electrophoresis remains the most widely used analytical method for high-resolution separation of DNA and other biological molecules. With the help of laser-induced fluorescence (LIF), the detection limit can be reduced to typical levels of 10−18 to 10−21 mol (Kostal, V.; Katzenmeyer, J.; Arriaga, E. A. Anal Chem 2008, 80, 4533-50; Frost, N. W.; Jing, M.; Bowser, M. T. Anal Chem 2010, 82, 4682-98) and single-molecule capillary electrophoresis SM-CE becomes possible (Haab, B. B.; Mathies, R. A. Anal Chem 1999, 71, 5137-45; Haab, B. B.; Mathies, R. A. Anal Chem 1995, 67, 3253-60; Effenhauser, C. S.; Bruin, G. J. M.; Paulus, A.; Ehrat, M. Analytical Chemistry 1997, 69, 3451-3457; Chen, D.; Dovichi, N. J. Analytical Chemistry 1996, 68, 690-696). Such techniques are limited by low mass detection efficiency (<1%), narrow DNA sizing dynamic range, the necessity for viscous sieving matrices, and the complexities of high voltage injection and separation schemes.
There thus remains a need for improved systems and methods for separating and determining sizes of particles in a sample.